This invention relates to a method and apparatus for recovering the polarization state of an incident light wave of arbitrary polarization reflected by a phase conjugate mirror; i.e., for obtaining true phase conjugation of a field of arbitrary polarization.
An optical wave propagating through a distorting medium can regain its original state by phase conjugation followed by reverse propagation through the distorting medium. A. Yariv, Appl, Phys. Lett. 28, 88 [1976], A. Yariv, Opt. Commun 21, 49, [1977]. However, the tensorial nature of the nonlinear constant .chi..sup.(3), and that of the electro-optic effect, make it impossible to perform true phase conjugation on fields with arbitrary polarization. It has been thought heretofore that true phase conjugation of fields with arbitrary polarization can be obtained only by separate phase conjugation of the individual transverse components of the field. P. Yeh, Opt. Commun., 51, 195 [1984]; I. McMichael, and M. Khoshnevisan, Technical Digest, Conference on Lasers and Electro-Optics, paper THN1 [1985]. An object of this invention is to provide true phase conjugation.